Color systems, such as the Munsell (see U.S. Pat. No. 824,374, incorporated fully hereinto by reference) and C.I.E. (Commission Internationale de l'Eclairage) systems, which use the three color coordinates of hue, intensity of saturation or chroma (hereinafter simply referred to as "chroma") and darkness/lightness value (hereinafter simply referred to as "value") are notoriously well known. In this connection, these color coordinate systems enable an essentially three-dimensional color model to be constructed whereby the characteristics of any color may be identified using its unique hue, chroma and value coordinates.
As may be appreciated, a three-dimensional "solid" color model is unwieldy since it is usually difficult to access and use the colors in the model's interior--that is, those colors closely adjacent to the value scale. Thus, various proposals have been made whereby three-dimensional color models are constructed which allow the interior colors in the model to be accessed. In this regard, please see U.S. Pat. No. 1,480,486 to Allen and U.S. Pat. No. 3,474,546 to Wedlake.
Other "two-dimensional" color systems have also been proposed as evidenced by U.S. Pat. No. 1,597,830 to Rueger, U.S. Pat. No. 1,612,791 to Ames et al, U.S. Pat. No. 1,617,024 to Munsell et al, and U.S. Pat. No. 2,007,264 to Allen. In essence, each of these systems provide for an organized two-dimensional arrangement of color patches printed upon an underlying substrate.
More recently, a color grading system for gemstones has been proposed in U.S. Pat. No. 4,527,895 to Rubin whereby so-called color-masking charts (each comprised of a series of sample achromatic color swatches printed upon a transparent flexible film substrate and arranged in increasing amounts of the achromatic color) may be overlaid with chromatic color charts (each comprised of a series of sample chromatic color swatches printed upon a transparent flexible film substrate in increasing intensities of color saturation) so as to closely approximate the color characteristics of particular gemstones.
However, since the system disclosed in the Rubin '895 patent necessarily depends upon color swatches printed upon a transparent substrate, the swatch is exposed to physical abrasion during use such that its integrity and/or quality may degrade over time. As a result, the accuracy of color matches using such a system will likewise degrade over time. In addition, the printed swatches often lack the clarity and/or intensity of color that is intended to be matched (i.e., since the color is presented "two-dimensionally" because of the thin films upon which the color swatches are printed) so that oftentimes only a close approximation of the actual color characteristics of the gemstones may be achieved.
Thus, it is towards providing more faithful and convenient gemstone color communication kits which the present invention is directed.
Broadly, the present invention is embodied in kits which assist in the subjective evaluation of color characteristics of precious and semi-precious gemstones, and which allow the evaluated color to then be objectively communicated to third parties. Once the color characteristics of a particular gemstone have been determined, for example, a matched gemstone having comparable color characteristics may be selected by a gem supplier who has not inspected the gemstone that was evaluated using the kits of this invention.
The present invention is preferably embodied in kit form which include an ordered set comprised of a number of simulated gemstones. Each of the simulated gemstones includes a multifaceted gemstone body portion (which preferably closely resembles a brilliant cut gemstone having 58 facets) and a handle portion radially extending from the body portion. The handle portion thus allows the multifaceted body portion to be manipulated in ambient light conditions so that its color characteristics can adequately be observed.
Each of the simulated gemstones is formed of a molded plastics material which exhibits unique color hue, chroma and value characteristics. Thus, within each hue, the chroma and value characteristics may be varied within an ordered set so as to achieve a close color match with natural gemstones.
The ordered sets of simulated gemstones are most preferably displayed in respective trays. Thus, the kits of this invention may be provided in multiple trays, with each tray being dedicated to a particular color set of simulated gemstones. The individual trays according to this invention will include an opposing pair of recesses which are sized and configured to accept therewithin the gemstone body portion and an opposing terminal end of the handle portion. The tray also includes a fulcrum surface against which a corresponding portion of the handle portion bears so that the gemstone body portion may be pivoted upwardly from its corresponding recess in response to downward pressure being applied against the handle portion's terminal end.
Further aspects and advantages of this invention will become more clear after careful consideration is given to the following detailed description thereof.